琳恩颱風豪雨研究

A Study of Heavy Rainfall Caused by Typhoon Lynn

曲克恭(Ko-Kung Chu) ； 陳正改(Cheng-Kai Chen)

《大氣科學》 16卷3期 (1988/09) Pp. 253-262

摘要

從民國76年10月23日至26日，琳恩（LYNN）颱風之外圍環流與東北季風共伴造成台灣北部及東北部地區之豪雨及洪水災害。此次持續性大雨（R ≥ 10 mm/hr）第一次約為44小時，第二次持續約8小時，二者相隔25小時，可能是輻合帶之北移，使輸送水汽之氣流改變方向，減弱地形抬昇作用所致。經比較分析過去相同類型颱風個案，發現此類路徑之颱風形成豪雨原因中最具效力者為颱風外圍環流與東北季風輻合氣流輸送水汽受地形之舉升作用，故豪雨量分布有較為固定的空間型態，常由大雨中心向外擴展。琳恩颱風形成之最大單點累積雨量，延時30分鐘以上者均大於民國70年「九三」水災者，但低於48年「八七」水災者，長時間累積之豪雨量形成嚴重水災。

關鍵字

豪雨量 ； 東北季風共伴 ； 時空分布

並列摘要

From October 23 to 26, 1987, the combined effects of the flow in the outskirts of typhoon Lynn and the North Eastern Monsoon caused heavy rain and flash flood in the northern and north-eastern Taiwan. The continuously heavy rain (R ≥ 10 mm/hr) happened two times. The first one held about 44 hours, and the second one occurred and lasted about 8 hours. Because the topography-lifting mechanism of moist air which was brought by the convergent current dominated the occurrence of heavy rain, it was found that there were relatively fixed patterns of the spatial distributions of heavy rainfall in the northern and north-eastern Taiwan when they were affected by a typhoon such as Lynn. The domain of heavy rainfall extended outwardly from a heavy rainfall center which almost held at the same location for the whole period of heavy rain. The cumulated maximum point rainfall above the duration of 30 minutes of Lynn case was greater than that of the Agnes case, September 3, 1981, and it was less than that of the Ellen case, August 7, 1959.

並列關鍵字

Heavy rainfall ； confronted with NE Monsoon ； Temporal and spatial distribution